Instance Method

removeObserver(_:forKeyPath:context:)

Raises an exception.

Declaration

func removeObserver(_ observer: NSObject, forKeyPath keyPath: String, context: UnsafeMutableRawPointer?)

Parameters

observer

The object to remove as an observer.

keyPath

A key-path, relative to the set, for which observer is registered to receive KVO change notifications. This value must not be nil.

context

Arbitrary data that is passed to observer in observeValue(forKeyPath:of:change:context:).

Discussion

NSSet objects are not observable, so this method raises an exception when invoked on an NSSet object. Instead of observing a set, observe the unordered to-many relationship for which the set is the collection of related objects.